Cannot import name 'maybe_sync'
## Describe the bug
Cannot seem to import datasets when running run_summarizer.py script on a VM set up on ovhcloud

## Steps to reproduce the bug
```python
from datasets import load_dataset
```

## Expected results
No error

## Actual results
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/opt/conda/lib/python3.7/site-packages/datasets/__init__.py", line 34, in <module>
    from .arrow_dataset import Dataset, concatenate_datasets
  File "/opt/conda/lib/python3.7/site-packages/datasets/arrow_dataset.py", line 48, in <module>
    from .arrow_writer import ArrowWriter, OptimizedTypedSequence
  File "/opt/conda/lib/python3.7/site-packages/datasets/arrow_writer.py", line 27, in <module>
    from .features import (
  File "/opt/conda/lib/python3.7/site-packages/datasets/features/__init__.py", line 2, in <module>
    from .audio import Audio
  File "/opt/conda/lib/python3.7/site-packages/datasets/features/audio.py", line 8, in <module>
    from ..utils.streaming_download_manager import xopen
  File "/opt/conda/lib/python3.7/site-packages/datasets/utils/streaming_download_manager.py", line 16, in <module>
    from ..filesystems import COMPRESSION_FILESYSTEMS
  File "/opt/conda/lib/python3.7/site-packages/datasets/filesystems/__init__.py", line 13, in <module>
    from .s3filesystem import S3FileSystem  # noqa: F401
  File "/opt/conda/lib/python3.7/site-packages/datasets/filesystems/s3filesystem.py", line 1, in <module>
    import s3fs
  File "/opt/conda/lib/python3.7/site-packages/s3fs/__init__.py", line 1, in <module>
    from .core import S3FileSystem, S3File
  File "/opt/conda/lib/python3.7/site-packages/s3fs/core.py", line 11, in <module>
    from fsspec.asyn import AsyncFileSystem, sync, sync_wrapper, maybe_sync
ImportError: cannot import name 'maybe_sync' from 'fsspec.asyn' (/opt/conda/lib/python3.7/site-packages/fsspec/asyn.py)

## Environment info
<!-- You can run the command `datasets-cli env` and copy-and-paste its output below. -->
- `datasets` version: 1.16.0
- Platform: OVH Cloud Tesla V100 Machine
- Python version: 3.7.9
- PyArrow version: 6.0.1
